Materials Literature
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Several bioclastic and oolitic carbonates have been studied with the transmission electron microscope. Aragonite has been distinguished from calcite on the basis of the SAD patterns and the morphology. The aragonite occurred either as microscopic crystals varying in length from 0.3 to I mm, or as larger masses twinned…
An example of the possible uses of the newly obtained, surprisingly stable title compound (1) is in the synthesis of the unsymmetric siloxane (2). At ca. 240°C (!) (1) forms the new, sterically very crowded cyclotrisiloxane (tBu2SiO)3.
A new technique has been developed to study the surface energy characteristics of small diameter fibres. This method is tensiometric and based on wetting properties in a two phase liquid system. Two types of carbon fibre have been investigated under both static and dynamic conditions in immersion and emersion. The hig…
Abstract The glass transition, rubbery modulus, and tensile behavior of poly(n‐butyl acrylate)/polystyrene interpenetrating polymer networks (IPN's), semi‐1 IPN's, and their corresponding random copolymer networks were studied as a function of both composition ratio and crosslink density. Two temperatures were selecte…
Abstract The sand and silt fractions of soils derived from Tertiary basalt in northeastern Ireland exhibit unusually high cation-exchange capacities. Smectite was identified by X-ray powder diffraction in all size fractions and was selectively dissolved by treatment with 1 N HCl and 0.5 N NaOH. Structural formulae, ba…
The influence of boundary conditions on the smectic A-C * phase transition has been studied. From a consideration of the free energy under the anchoring condition with planar orientation of moelcules on two boundaries, it is shown that the phase transition temperature from the smectic-A to smectic-C phases decreases w…
The siliceous valve of Hantzschia is briefly described, preparatory to following its morphogenesis. While Hantzschia is morphologically very different to Pinnularia, there are several subtle but important similarities in detail. Bundles of microfilaments, significant in generating the gliding motion of these cells, li…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectronic structure of metalloporphyrins. 1. Experimental electron density distribution of (meso-tetraphenylporphinato)cobalt(II)Edwin D. StevensCite this: J. Am. Chem. Soc. 1981, 103, 17, 5087–5095Publication Date (Print):August 1, 1981Publication History Published online1…
Magnetic field dependences of the first and the second uniaxial magnetocrystalline anisotropy constants K u1 and K u2 for hcp Co were obtained at various temperatures between 4.2 and 616 K by using the 90-points least mean square routine. It was found that the contribution of the Fermi level-dependent term to d K u1 /…
Abstract In Anlehnung an eine phänomenologische thermokinetische Fluktuationstheorie des Glasübergans wird ein Ansatz zur Beschreibung des Einfriervorgangs und von Nachwirkungserscheinungen im Rahmen der linearen Reaktion vorgestellt. Anhand der Auswertung von Thermogrammen \documentclass{article}\pagestyle{empty}\beg…
Abstract The release of norethindrone from a poly(ortho ester) derived from 3,9‐bis(methylene)2,4,8,10‐tetraoxaspiro[5,5] undecane and 1,6‐hexanediol was studied. Thin circular devices containing incorporated drug and a water soluble salt, such as sodium carbonate, sodium sulfate, or sodium chloride, were placed in wa…
The theory of inelastic electron tunnelling spectroscopy (IETS) and the suitability of this technique for examining adhesive-aluminium oxide interfaces are discussed. IET spectra are presented of an epoxide resin (the diglycidyl ether of bisphenol A), two aliphatic amine hardeners (di-[1 -aminopropyl-3-ethoxy] ether a…
Transport and phosphorylation of glucose via enzymes II-A/II-B and II-BGlc of the phosphoenolpyruvate:sugar phosphotransferase system are tightly coupled in Salmonella typhimurium. Mutant strains (pts) that lack the phosphorylating proteins of this system, enzyme I and HPr, are unable to transport or to grow on glucos…
Cathodic electrochromism of lutetium diphthalocyanine films on insulating substrates was investigated by a moving‐boundary technique. Reduction occurred by injection of electrons from a gold contact and cations from a liquid electrolyte. Light blue products formed with aqueous or organic solutions of alkali metal salt…
X-ray and neutron scattering techniques have been used to investigate the spin Peierl's transition in $N$-methyl-$N$-ethyl-morpholinium bistetracyanoquinodimethane [MEM ${(\mathrm{TCNQ})}_{2}$]. Both techniques reveal a doubling of the $c$-axis stacking of the TCNQ molecules below the transition. Diffuse x-ray scatter…
(1981). Mixed Valency Chemistry: A Survey of 10 Years Progress. International Reviews in Physical Chemistry: Vol. 1, No. 2, pp. 149-193.
Abstract Structural models for glasses of the TeO 2 –MoO 3 system are suggested. On the basis of X‐ray and infrared spectral investigations, by comparing with known crystalline structures of TeO 2 , MoO 3 and Te 2 MoO 7 (T 2 M), it is shown that the glasses from TeO 2 to Te 2 MoO 7 possess [TeO 4 ] and [MoO 5 ] groups…
Quantitative results for the correlation functions for the Lorentz model of overlapping hard spheres are worked out and discussed within the recently proposed theory of diffusion and localization of a classical particle moving in a random static field. The applicability of the theory to the diffusion phase is establis…
We have shown that the silk fibroin gene from Bombyx mori is faithfully transcribed in an in vitro transcription system of the HeLa cell extract prepared by the method of Manley et al. [Manley, J. L., Fire, A., Cano, A., Sharp, P. A. & Gefter, M. L. (1980) Proc. Natl. Acad. Sci. USA 77, 3855-3859]. Using this system a…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMultinuclear nuclear magnetic resonance study of three aqueous lanthanide shift reagents: complexes with EDTA and axially symmetric macrocyclic polyamino polyacetate ligandsCharles C. Bryden, Charles N. Reilley, and Jean F. DesreuxCite this: Anal. Chem. 1981, 53, 9, 1418–142…